The invention concerns a refrigerating fluid loop, notably for an air conditioning installation for a vehicle passenger compartment, comprising a compressor able to raise the pressure of the fluid to the gaseous state, a condenser able to condense the fluid compressed by the compressor and to sub-cool it to the liquid state, a separating reservoir able to separate the residual gas from the fluid in the liquid state coming from the condenser, a pressure reducer able to reduce the pressure of the fluid leaving the reservoir and an evaporator able to cause the fluid coming from the pressure reducer to change from the liquid state to the gaseous state before it returns to the compressor.